“Spiders
spin webs because they are spiders, and we humans eat the way we do and
like the foods we do because we’re humans.” Susan B. Roberts,
PhD, The Instinct Diet (Workman, 2008)

Calories Matter, But Instinctive Behavior
Matters More

* * *

Carbs also Matter—to the Brain

You probably heard about the new finding that equal-calorie
diets with different amounts of carbohydrate, fat, and protein (high, low, or
moderate) caused essentially the same weight loss. All that matters, it seems,
is calories in and calories out. Macro-nutrient composition doesn’t make any
difference. You may not have heard, however, that weight loss from all diet
combinations stopped after six months; at two years the dieters had regained
half the loss and were on the way to regaining the entire loss. All of the
dietary mixes are apparently failing.

Let’s look at the new study, and then talk about an
approach that does work.

More than 800 overweight adults volunteered for one of four
eating plans roughly equivalent to popular diets such as Atkins (low carbs),
Ornish (low fat), Mediterranean (moderate fat, mostly vegetarian) and Zone
(40-30-30). All diets included the same heart-healthy foods, but in different
proportions. To minimize the effect of outside influences, the researchers
avoided direct reproduction of the popular diets; for example, none of the diets
were higher than 40% fat, or lower in carbohydrate and protein than 35% and 15%,
respectively. All participants were advised to exercise at a moderate level 90
minutes a week. Each plan was designed to create a 750 calorie deficit each day.
The study ran for two years, unusually long for an intervention study. All
participants were offered regular diet counseling.

Results were essentially the same for all four diet groups.
Reported satiety, hunger, and satisfaction were also similar.

Participants lost an average of 13 pounds at six months,
but began regaining weight after one year. At two years, the average loss was
down to about nine pounds and two inches around the waist. Many had returned to
their former eating habits. The participants apparently couldn’t stick to any of
the diet plans.

In an accompanying editorial, Martijn B. Katan, PhD,
stressed that the subjects had difficulty adhering to the assigned ratios.
“Protein intake was intended to differ by 10%,” Katan wrote, “but the actual
difference as assessed by measurement of urinary nitrogen excretion, was 1 to
2%.” In addition, he says, objective measurements showed that carbohydrate and
fat intake goals were not achieved.

It is helpful to know that calorie-count is what matters.
But what difference does it make if people can’t, or won’t, stick to calorie (or
macro-nutrient) goals? For all intents and purposes, we are back to square one.

“Even these highly motivated, intelligent participants who
were coached by expert professionals could not achieve the weight loss needed to
reverse the obesity epidemic,” Dr. Katan of Amsterdam’s Free University was
forced to conclude. (Those who attended counseling sessions regularly throughout
the study were significantly more likely to lose weight.)

“The effect of any particular diet group was minuscule, but
the effect of individual behavior is humongous,” said Frank M. Sacks, MD, lead
author of the study and professor of cardiovascular disease prevention at
Harvard School of Public Health. “We had some people losing 50 pounds, and some
people gaining 5 pounds. That’s what we don’t have a clue about. I think in the
future, researchers should focus…on finding what is really the biggest governor
of success in these individuals.”

Good idea.

Let’s look at the work of Susan B. Roberts, PhD, professor
of nutrition and psychiatry at Tufts University, who has studied basic food
instincts which control how we eat. The answer, says Roberts, lies in managing
the controls. Her book, The Instinct Diet (Workman, 2008) tells you how
to control the controls. (Hint: You don’t have to suffer to lose weight and keep
it off. Being hungry and feeling deprived are not part of the deal.)

The Five Food Instincts

Dr Roberts has been studying the science of nutrition and
weight loss for 20 years—she has run a research laboratory at Tufts University
in Boston for 17 of those years—and has found “striking agreement” that five
things affect our eating behavior: “hunger, the availability of
food, the variety of food, the familiarity of food, and how rich
or calorie-dense the food is.”

“We cannot [override] these instincts,” she says. But once
we understand the signals that trigger them, “we can get our food instincts to
work for us, not against us, in the battle against excess weight.”

We know from the new study that there is no magic
macronutrient balance. High or low carb, or fat, or protein doesn’t make it
easier to control calorie intake. So what is the answer?

“Controlling the signals received by our food brain from
our body and sensory centers is the key to getting all our food
instincts, including hunger, working for us,” says Roberts. There is more than
one way to signal our brain that we’ve had enough to eat, without overshooting
our calorie needs.

“There are four effective ways to accomplish this,” says
Roberts: high-fiber, high-protein, low-Glycemic Index, and volume. She
recommends using them all; that's important, you'll need all four methods to
stay satisfied.

It’s well-known that fiber in the diet makes you feel full;
see
http://www.cbass.com/fiber.htm Roberts recommends including high fiber
foods (grains, cereal, beans, vegetables, fruits) in most meals. “Do be sure to
drink six to eight glasses of water daily when you eat more fiber,” she
counsels, “to get the full benefits and prevent constipation.” It’s the
water-holding property that makes fiber so filling. (Water, of course, takes up
space but contains no calories.)

Foods high in protein, such as fish or chicken, are also
very satisfying, and slow the return of hunger. They are digested slowly and
don’t cause large fluctuations in blood sugar. Unlike many carbohydrate sources,
protein foods are digested over hours rather than minutes. Roberts suggests
combining fish or chicken with green vegetables or salad. “The trouble with
high-protein diets,” she warns, “is that they can get really boring…The
temptation to cheat may get stronger and stronger.”

That’s why she suggests making high-protein one of many
options. “You can go to a restaurant and have half a lean entrée with a side
salad and a glass of mineral water and keep your diet without making a public
fuss about it.” (Carol and I frequently enjoy this option when eating out, but
we usually have salad and vegetables.)

Low-glycemic foods, which cause only a small rise in blood
sugar, are another good option for controlling how much we eat. “Low-GI foods
have been shown to suppress hunger extremely well,” Roberts explains, “because
the more stable blood glucose produced by these foods tells our food brain that
all is well and we don’t need to eat again yet.”

Another alternative (which is suggested in Challenge
Yourself) is combining low-GI foods with high-GI foods for taste. Roberts
says, “Low-GI foods, when eaten alone, may not taste as good as foods with
higher GI values. They’re digested more slowly, so our brain learns to like them
but not love them, probably because they don’t release as many of the feel-good
taste and reward chemicals.”

A steady diet of low-GI foods will “tempt you to cheat,”
Roberts warns. “We…seem to instinctively crave carbohydrates, and any plan that
doesn’t have a way to give you some carbs in a healthy form will be
fundamentally unsatisfying after a while.” (More about the need for carbs below)

The fourth and last way to deal with hunger is “volume.”
Pioneered by Volumetrics author Barbara Rolls
http://www.cbass.com/volumetrics.htm , this method of controlling hunger
relies on the fact that volume trumps calories in making us feel full. “The
mechanism isn’t known for sure,” says Roberts, “but is probably related to the
activation of stretch receptors in the stomach or simply our perception of the
right amount of food. As long as food is bulky, it doesn’t matter as much
where the majority of calories come from.”

Good high-volume options, according to Dr. Roberts, are
high-fiber cereal with low-fat milk, soup with dense particles to slow down
digestion, and large dinner-size salads with something substantial on top, such
as grilled chicken breast, seeds, or nuts. Something chewy is good, because
chewing helps to make you feel full and satisfied.

Remember, don’t pick one or two ways to cope with the
hunger instinct, use all four (fiber, protein, low-GI, and volume) to make sure
every meal or snack makes you feel full and satisfied—without giving you too
many calories.

I’ve given lots of details on managing the hunger instinct,
because it is clearly the basic food instinct. Dealing with it puts us
well on the way to controlling the other four instincts, which we’ll cover
briefly.

AVAILABILITY: This one is pretty straightforward. If food
is there, we’re programmed to eat it. It’s the basis for my practice of putting
on the table only the food I plan to eat. If I want more, I get up and get
it—but I stop and think about it first. I almost always decide I’ve had all I
really want. That simple rule has saved me from eating many thousands of
excess calories.

Dr. Roberts explains that this instinct came into being
thousands of years ago. “This was essential for survival, and the most
successful survivors were those who ate whenever food was available.”

“So it’s up to you to avoid temptation by getting rid of
what tempts you,” says Roberts. It’s as simple as that. Get the bad stuff out of
your home—and don’t buy more. If you really crave an ice cream sundae or a deep
dish pizza, go out and have it. Just don’t make a habit of it.

CALORIE DENSITY: Those who have read my first book
Ripped will remember my cardinal rule: “Avoid concentrated calories.” I
discovered that by eating only whole, unprocessed foods, you avoid almost all
concentrated calorie foods, and you won’t overeat.

That’s still my rule.

“Almost everybody loves high-calorie foods, but does this
mean we’re instinctively attracted to foods that are jam-packed with
calories?” Roberts asks rhetorically. “You bet it does,” she states
unequivocally.

Again, it goes back to ancient times, according to Dr.
Roberts. “An affinity for foods loaded with calories was an asset during early
human development, when the next meal was an unpredictable event,” she explains.
“The more calories per ounce a food has, the more we prefer it.”

Macronutrients don’t seem to matter, says Roberts. “In
fact, the most popular foods are actually a mixture of [carbs, fat and
protein]…Our strongest preferences are for foods containing some of those
rapidly digested white carbs, with a little fat and protein thrown in for good
measure.”

Attempting to avoid calorie dense food altogether is not a
good idea, however. It won’t work. The key is to recognize the danger and be
careful not to overdo. As noted, I eat mainly whole, unprocessed foods—and only
have an occasional sweet treat.

An occasional splurge can actually be beneficial,
because it gets the craving out of your system, allowing you to happily go back
to healthy eating most of the time. It works for me on major holidays. I eat my
fill, and then go back to normal eating the next day. The second part is the
key, of course.

You’ll find other good suggests for avoiding calorie-dense
foods in Dr. Roberts’ book.

FAMILIARITY: My practice of eating frequent meals and
snacks to stay ahead of the hunger curve—and in control—dovetails with this
instinct. I could just as easily make a habit of skipping breakfast, snacking
haphazardly during the day, and stuffing myself in the evening—but it wouldn’t
help me control how much I eat.

The same is true of the kind of food we usually eat. You
can make a habit of eating healthy meals, or Coke, burgers and fries.

“Instinctively, we’re drawn to what we know,” she explains.
“Historically, this instinct kept us safe. For our Paleolithic ancestors, being
cautious about trying new foods was all that stood between a good dinner and
death by poison.”

You can change, however. Start eating healthy, regular
meals and pretty soon you’ll get used to it—and actually prefer eating that way.

“Learn to love what’s good for you,” Roberts suggests.
“Repetition is all it takes.” Try it. You’ll like it.

To learn more about this instinct and how to make it work
for you, read Dr. Roberts’ book.

VARIETY: We are programmed to eat a widely. Again, it was a
matter of survival. “Because no single food has all the nutrients that humans
need, it was essential for them to eat a wide variety of foods in order to get
the healthy nutrition that would keep them alive,” Roberts explains. “Variety
instinctively felt right.”

Like the other food instincts, this one can work for or
against us.

Too much variety leads to over eating. “Even fish and other
wild creatures eat more food when they’re presented with more variety,” Roberts
tells us. “In study after study, variety has been shown to have a huge effect on
the amount of food we eat.”

This instinct is closely related to the “availability”
instinct. The difference is that availability relates to amount, and variety
relates to, well, variety. The key is to understand that both instincts are in
play.

Not surprisingly, the fixes are much the same. Variety can
be good if it’s the right kind. Roberts and her colleagues at the Tufts lab
“discovered that eating a wide variety of high calorie foods…leads to weight
gain. Conversely, eating a greater variety of vegetables can double or triple
total vegetable consumption, which in turn reduces overall calorie intake.”

So the answer to both instincts is to replace the bad stuff
with the good stuff. A wide variety of junk food is likely to make you fat, but
a house with lots of fruits, vegetables, whole grains, beans, fish, seeds, and
nuts will help you become and stay lean.

You can take it from there.

You’ll find many more motivational and behavioral tips,
along with a three-stage program with menus for omnivores and vegetarians, in
Roberts’ new book, The Instinct Diet.

Take it from Dr. Roberts—and me—managing your food
instincts is far more important than calorie counting or whether you eat a
low-fat or a low-carb diet.

Before wrapping our discussion, we promised to talk about
the need for carbs. I want to briefly tell you about an up-to-the-minute study
spotlighting a danger inherent in low-carb eating.

Cut Carbs, Starve Your Brain

In Ripped, I told about an episode where cutting
carbs to practically zero left me so tired that I couldn’t think straight.
Eating two nectarines brought me out of the stupor; it literally made me feel
“like a new person.” Interestingly, I didn’t remember the details until Carol
filled me in while I was writing Ripped. Except for feeling very tired, I
apparently thought I was doing okay. About all I remembered clearly was being
miraculously revived after eating the nectarines.

My explanation after gathering all the facts: “The
carbohydrates in the nectarines were easily converted to the glucose (blood
sugar) that my brain required to function properly.” A study by researchers at
Tufts University (Appetite, February 2009) suggests a more complete—and
interesting—analysis.

The researchers compared 19 women who were allowed to
choose a low-carb diet (similar to Atkins) or a reduced-calorie balanced diet
recommended by the American Dietetic Association (ADA). Nine of the women
selected the Atkins-style diet and 10 chose the ADA diet. The low-carb group was
instructed to cut carbs completely for the first week, add 5-8 grams per day in
week two, and an additional 5-8 g in the third week (total 10-16 g of carbs per
day). The ADA group was advised to calculate their calorie intake based on their
bodyweight, while conforming to the recommended daily allowance for carbs: 130
grams, based in part on what the brain needs for food.

All of the women were tested using a battery of assessments
for cognitive function (confusion, memory, attention, and others) 72 hours
before starting the diets, and again 48 hours and one, two, and three weeks
after going on the diets. They were then retested two and three weeks after
carbohydrates were reintroduced to the low-carb dieters.

The Tufts researchers “proposed that dietary carbohydrate
restriction would impair cognitive performance in the early phases of the diet,
and that this impairment would be [reversed] by reintroduction of carbohydrate.”

As background, the researchers explained that the brain’s
primary fuel is glucose, which isn’t stored in the brain, and must be supplied
from limited amounts of glycogen stored in the liver and muscle tissue—and
carbohydrates in the diet. Importantly, glucose can not be metabolized from fat.

“The body will consume its glycogen stores in a matter of
1-2 days,” the scientists explained. Earlier research on epilepsy sufferers and
animals, they added, suggests that carbohydrate restriction “can profoundly
influence brain functioning.”

“Although the study had a modest sample size, the results
showed a clear difference in cognitive performance as a function of diet,” Holly
A. Taylor, PhD, corresponding author of the study, is quoted as saying in
Tufts Health & Nutrition Letter.

The details, as revealed in the report, are very
interesting.

Confusion ratings were a mixed bag. The low-carb group
reported somewhat more confusion at 48 hours and 3 weeks, but the ADA dieters
were significantly more confused during the middle portion of the study, at 1
week and 2 weeks. (Calorie restriction is not without consequences.) Consistent
with previous studies, the low-carb dieters outperformed the ADA group in
attention tests. (Protein produces alertness, carbohydrates less tension/more
calmness.) On all other measures, however, the ADA group outperformed. Those on
the low-carb diet suffered a gradual decrease in memory performance and scored
slower reaction times on all tests.

The researchers concluded: “The current study suggests that
the macronutrient makeup of various weight-loss regimens are likely to have both
positive and negative effects on our ability to think, attend, and remember.”

Sounds like a balanced diet, with ample carbs and protein,
would be the best bet.

* * *

These findings seem to explain with my low-carb blackout.
My analysis in Ripped was right on, as far as it went. My brain was
showing all the signs of carb starvation.